44 JOANNA E. M. SALE ET AL.
Some people would say that we are beyond the debate and can now freely use
mixed- method designs to carry out relevant and valuable research. According to
Carey (1993), quantitative and qualitative techniques are merely tools; integrating
them allows us to answer questions of substantial importance. However, just be-
cause they are often combined does not mean that it is always appropriate to do
We believe that mixed-methods research is now being adopted uncritically by
a new generation of researchers who have overlooked the underlying assumptions
behind the qualitative-quantitative debate. In short, the philosophical distinctions
between them have become so blurred that researchers are left with the impression
that the differences between the two are merely technical (Smith and Heshius,
Combining qualitative and quantitative methods in a single study is widely prac-
ticed and accepted in many areas of health care research. Despite the arguments
presented for integrating methods, we will demonstrate that each of these methods
is based on a particular paradigm, a patterned set of assumptions concerning reality
(ontology), knowledge of that reality (epistemology), and the particular ways of
knowing that reality (methodology) (Guba, 1990). In fact, based on their paradig-
matic assumptions, the two methods do not study the same phenomena. Evidence
of this is reﬂected by the notion that quantitative methods cannot access some of
the phenomena that health researchers are interested in, such as lived experiences
as a patient, social interactions, and the patients’ perspective of doctor-patient inter-
actions. The information presented in this paper is not new in the sense that we are
making a “new” case for or against the debate. Rather, based on the paradigmatic
differences concerning the phenomenon under study, we propose a "new" solution
for using mixed-methods in research that we believe is both methodologically and
2. The Two Paradigms
The quantitative paradigm is based on positivism. Science is characterized by
empirical research; all phenomena can be reduced to empirical indicators which
represent the truth. The ontological position of the quantitative paradigm is that
there is only one truth, an objective reality that exists independent of human
perception. Epistemologically, the investigator and investigated are independent
entities. Therefore, the investigator is capable of studying a phenomenon without
inﬂuencing it or being inﬂuenced by it; “inquiry takes place as through a one
way mirror” (Guba and Lincoln, 1994: 110). The goal is to measure and analyze
causal relationships between variables within a value-free framework (Denzin and
Lincoln, 1994). Techniques to ensure this include randomization, blinding, highly
REVISITING THE QUANTITATIVE-QUALITATIVE DEBATE 45
structured protocols, and written or orally administered questionnaires with a lim-
ited range of predetermined responses. Sample sizes are much larger than those
used in qualitative research so that statistical methods to ensure that samples are
representative can be used (Carey, 1993).
In contrast, the qualitative paradigm is based on interpretivism (Altheide and
Johnson, 1994; Kuzel and Like, 1991; Secker et al., 1995) and constructivism
(Guba and Lincoln, 1994). Ontologically speaking, there are multiple realities
or multiple truths based on one’s construction of reality. Reality is socially con-
structed (Berger and Luckmann, 1966) and so is constantly changing. On an
epistemological level, there is no access to reality independent of our minds, no
external referent by which to compare claims of truth (Smith, 1983). The invest-
igator and the object of study are interactively linked so that ﬁndings are mutually
created within the context of the situation which shapes the inquiry (Guba and
Lincoln, 1994; Denzin and Lincoln, 1994). This suggests that reality has no exist-
ence prior to the activity of investigation, and reality ceases to exist when we no
longer focus on it (Smith, 1983). The emphasis of qualitative research is on process
and meanings. Techniques used in qualitative studies include in-depth and focus
group interviews and participant observation. Samples are not meant to repres-
ent large populations. Rather, small, purposeful samples of articulate respondents
are used because they can provide important information, not because they are
representative of a larger group (Reid, 1996).
The underlying assumptions of the quantitative and qualitative paradigms result
in differences which extend beyond philosophical and methodological debates. The
two paradigms have given rise to different journals, different sources of funding,
different expertise, and different methods. There are even differences in scientiﬁc
language used to describe them. For example, the term “observational work” may
refer to case control studies for a quantitative researcher, but to a qualitative re-
searcher it would refer to ethnographic immersion in a culture. “Validity” to a
quantitative researcher would mean that results correspond to how things really are
out there in the world, whereas to a qualitative researcher “valid” is a label applied
to an interpretation or description with which one agrees (Smith and Heshusius,
1986). Similarly, the phrase “research has shown . . . ” or “the results of research
indicate . . . ” refers to an accurate reﬂection of reality to the quantitative researcher,
but to a qualitative researcher it announces an interpretation that itself becomes
reality (Smith and Heshusius, 1986).
The different assumptions of the quantitative and qualitative paradigms ori-
ginated in the positivism-idealism debate of the late 19th century (Smith, 1983).
The inherent differences rarely are discussed or acknowledged by those using
mixed-method designs. The reasons why may be because the positivist paradigm
has become the predominant frame of reference in the physical and social sci-
ences. In addition, research methods are presented as not belonging to or reﬂecting
paradigms. Caracelli and Greene (1993) refer to mixed-method designs as those
where neither type of method is inherently linked to a particular inquiry paradigm
46 JOANNA E. M. SALE ET AL.
or philosophy. Guba and Lincoln (1989) claim that questions of method are second-
ary to questions of paradigms. We argue that methods are shaped by and represent
paradigms that reﬂect a particular belief about reality. We also maintain that the
assumptions of the qualitative paradigm are based on a worldview not represented
by the quantitative paradigm.
3. Arguments Presented for Mixed-Method Research
Having discussed some of the basic philosophical assumptions of the two
paradigms, we are better able to address the arguments given for combining quant-
itative and qualitative methods in a single study. There are several viewpoints as
to why qualitative and quantitative methods can be combined. First, the two ap-
proaches can be combined because they share the goal of understanding the world
in which we live (Haase and Myers, 1988). King et al. (1994) claim that both
qualitative and quantitative research share a uniﬁed logic, and that the same rules
of inference apply to both.
Second, the two paradigms are thought to be compatible because they share
the tenets of theory-ladenness of facts, fallibility of knowledge, indetermination
of theory by fact, and a value-ladened inquiry process. They are also united by a
shared commitment to understanding and improving the human condition, a com-
mon goal of disseminating knowledge for practical use, and a shared commitment
for rigor, conscientiousness, and critique in the research process (Reichardt and
Rallis, 1994). In fact, Casebeer and Verhoef (1997) argue we should view qual-
itative and quantitative methods as part of a continuum of research with speciﬁc
techniques selected based on the research objective.
Third, as noted by Clarke and Yaros (1988), combining research methods is
useful in some areas of research, such as nursing, because the complexity of
phenomena requires data from a large number of perspectives. Similarly, some re-
searchers have argued that the complexities of most public health problems (Baum,
1995) or social interventions, such as health education and health promotion pro-
grams (Steckler et al., 1992), require the use of a broad spectrum of qualitative and
Fourth, others claim that researchers should not be preoccupied with the
quantitative-qualitative debate because it will not be resolved in the near future,
and that epistemological purity does not get research done (Miles and Huberman,
None of these arguments adequately addresses the underlying assumptions be-
hind the paradigmatic differences between qualitative and quantitative research.
However, Reichardt and Rallis (1994) acknowledge the possibility of contention
between the two paradigms concerning the nature of reality by conceding that the
two paradigms are incompatible if the qualitative paradigm assumes that there are
no external referents for understanding reality. We have argued that the qualitative
paradigm does assume that there are no external referents for understanding reality.
REVISITING THE QUANTITATIVE-QUALITATIVE DEBATE 47
Therefore, we propose that in addressing this fundamental assumption, Reichardt
and Rallis dismiss their own claim of compatibility between methodological
An interesting argument has been made by Howe (1988) who suggests that
researchers should forge ahead with what works. Truth, he states, is a normative
concept, like good. Truth is what works. This appears to be the prevalent attitude in
mixed- methods research. Howe’s argument seems to suggest that only pragmatists,
or those not wedded to either paradigm, would attempt to combine research meth-
ods across paradigms. But this does not address the issue of differing ontological
assumptions of the two paradigms.
A more interesting and complicated issue is the explanation of results from
studies using qualitative and quantitative methods which appear to agree. How can
the results be similar if the two paradigms are supposedly looking at different phe-
nomena? Achieving similar results may be merely a matter of perception. In order
to synthesize results obtained via multiple methods research, people often simplify
the situation under study, highlighting and packaging results to reﬂect what they
think is happening. The truth is we rarely know the extent of disagreement between
qualitative and quantitative results because that is often not reported. Another pos-
sibility which may account for seemingly concordant results could be that both
are, in fact, quantitative. Conducting a frequency count on responses to open-ended
questions is not qualitative research. Given the overwhelming predominance of the
positivist worldview in health care research, this is not surprising. This often trans-
lates to the misapplication of the canons of good “science” (quantitative research)
to qualitative studies (see Sandelowski, 1986).
Perhaps the only convincing argument for mixing qualitative and quantitative
research methods in a single study would be to challenge the underlying assump-
tions of the two paradigms themselves. A sound argument would be that both
qualitative and quantitative paradigms are based on the tenets of positivism, not
constructivism or interpretivism. Howe (1992) gives the impression of making this
argument by denying there is an “either-or” choice to be made. Rather, he claims,
both quantitative and qualitative researchers should embrace positivism coloured
by a certain degree of interpretivism, an adjustment which he proposes is made
possible by the critical social research model (or the critical educational research
model) which eschews the positivist-interpretivist split in favour of compatibility.
A legitimate argument would have been for Howe and others who appear to
be leaning toward this position (e.g. Reichardt and Rallis, 1994) to claim that the
paradigmatic debate was oversimpliﬁed by a positivism-interpretivism split, and
that the qualitative paradigm actually espoused positivism. If we take the position
that qualitative researchers operate within a positivist world, we could argue that
such a position actually negates or undermines the quantitative-qualitative debate
in the ﬁrst place because it does away with the beliefs about reality from which
qualitative research arose. We believe, however, that one cannot be both a positivist
and an interpretivist or constructivist.
48 JOANNA E. M. SALE ET AL.
Closely tied to the arguments for integrating qualitative and quantitative ap-
proaches are the reasons given for legitimately combining them. Two reasons
for this are prevalent in the literature. The ﬁrst is to achieve cross-validation or
triangulation – combining two or more theories or sources of data to study the
same phenomenon in order to gain a more complete understanding of it (Denzin,
1970). The second is to achieve complementary results by using the strengths of
one method to enhance the other (Morgan, 1998). The former position maintains
that research methods are interdependent (combinant); the latter, that they are in-
dependent (additive). Although these two reasons are often used interchangeably
in the literature, it is important to make a distinction between them.
4. The Phenomenon of Study
It is probably safe to say that certain phenomena lend themselves to quantitative as
opposed to qualitative inquiry and vice versa in other instances. Both quantitative
and qualitative researchers often appear to study the same phenomena. However,
these researchers’ deﬁnition of what the phenomena are and how they can best be
described or known differ. Both paradigms may label phenomena identically, but in
keeping with their paradigmatic assumptions, these labels refer to different things.
For the quantitative researcher, a label refers to an external referent; to a qual-
itative researcher, a label refers to a personal interpretation or meaning attached
to phenomena. For example, a quantitative researcher might use a factory record
as if it were representative of what actually happens in the workplace, whereas a
qualitative researcher might interpret it as one of the ways that people in a factory
view their work environment (Needleman and Needleman, 1996). Because there
is no external referent with which to gauge what the truth is, there is no interest
in assessing the record as representative of the one and only reality in the work-
place. Rather, the ways people use and describe it are expected to vary due to
people’s differing realities based on such characteristics as gender, age, or role
(e.g., employer, manager, worker). Another example is surgical waiting lists. To a
quantitative researcher, the list is like a bus queue; patients are taken off the list
based on the urgency of need for surgery or some other factors. To a qualitative
researcher, the key to understanding the meaning of the list rests with determining
how it is organized, managed and used by the people who actively create and
maintain it (Pope and Mays, 1993).
These two examples demonstrate that although qualitative and quantitative
paradigms may use common labels to refer to phenomena, what the labels refer to
is not the same. There are differences of phenomena within each paradigm as well.
However, the differences in phenomena between the two paradigms are philosoph-
ical differences, whereas the difference in phenomena within each paradigm are
not. Within the quantitative paradigm, we may compare the results of a magnetic
resonance imaging (MRI) scan to those of a computed tomography (CT) scan.
Although they may appear to reveal different realities, the use of the scans assumes
REVISITING THE QUANTITATIVE-QUALITATIVE DEBATE 49
that there is something to measure that exists independent of our minds. Both
scans are trying to approximate or capture the one reality which correlates with
the phenomenon of interest. Within the qualitative paradigm, one may compare
the results of a phenomenological study to those of a grounded theory study on
how nurses cope with the deaths of their patients. These two types of qualitative
studies do not assume that external referents for coping skills exist independent of
Having taken the position that the quantitative and qualitative paradigms do not
study the same phenomena, it follows that combining the two methods for cross-
validation/triangulation purposes is not a viable option. (Cross validation refers to
combining the two approaches to study the same phenomenon). Ironically, in a
comprehensive review of mixed-method evaluation studies, Greene and Caracelli
(1989) found that methodological triangulation was actually quite rare in mixed-
method research, used by only 3 of 57 studies. Combining the two approaches
in a complementary fashion is also not advisable if the ultimate goal is to study
different aspects of the same phenomenon because, as we argue, mixed-methods re-
search cannot claim to enrich the same phenomenon under study. The phenomenon
under study is not the same across methods. Not only does cross-validation and
complementarity in the above context violate paradigmatic assumptions, but it also
misrepresents data. Loss of information is a particular risk when attempts are made
to unite results from the two paradigms because it often promotes the selective
search for similarities in data.
5. Further Considerations in Mixed-Method Research Designs
The most frequently used mixed-method designs start with a qualitative pilot
study followed by quantitative research (Morgan, 1998). This promotes the mis-
perception that qualitative research is only exploratory, cannot stand on its own,
and must be validated by quantitative work because the latter is “scientiﬁc” and
studies truth. In response, qualitative researchers have increasingly tried to defend
their work using quantitative criteria, such as validity and reliability, as deﬁned
in quantitative studies. They also increasingly use computer programs speciﬁc-
ally designed for analysing qualitative data, such as NUD.IST or Ethnograph, in
quantitative (counting) ways. These practices seriously violate the assumptions
of the qualitative paradigm(s). For research to be valid or reliable in the narrow
(quantitative) sense requires that what is studied be independent of the inquirer and
be described without distortion by her interests, values, or purposes (Smith and
Heshusius, 1986). This is not how qualitative studies unfold. They are based on the
minimum distance between the investigator and the investigated, and seek multiple
deﬁnitions of reality embedded in various respondents’ experiences. Therefore, it
is more appropriate for qualitative researchers to apply parallel but distinct canons
of rigor appropriate to qualitative studies (Strauss and Corbin, 1990).
50 JOANNA E. M. SALE ET AL.
It is difﬁcult to say whether the growing trend of quantifying qualitative research
is a direct result of mixing quantitative and qualitative approaches. It does seem to
be a result of researchers from the two paradigms attempting to work together, or
the desire for qualitative research to be “taken seriously” in the world of positivist
research, such as is commonly found in medicine. In our opinion, mixing research
methods across paradigms, as is currently practiced, often diminishes the value of
both methods. Pressure is being exerted from the quantitative camp for qualitative
research to “measure up” to its standards without understanding the basic premises
of qualitative investigations. Proponents of the qualitative paradigm need to ad-
dress this pressure, but “without slipping on the mantle of quantitative inquiry”
(Smith and Heshusius, 1986: 10). This pressure will no doubt continue to escalate
as combined methods research becomes more common.
6. Our Solution
The key issues in the quantitative-qualitative debate are ontological and epistem-
ological. Quantitative researchers perceive truth as something which describes an
objective reality, separate from the observer and waiting to be discovered. Qualit-
ative researchers are concerned with the changing nature of reality created through
people’s experiences – an evolving reality in which the researcher and researched
are mutually interactive and inseparable (Phillips, 1988b). Because quantitative and
qualitative methods represent two different paradigms, they are incommensurate.
As Guba states, “the one [paradigm] precludes the other just as surely belief in a
round world precludes belief in a ﬂat one” (1987: 31). Fundamental to this view-
point is that qualitative and quantitative researchers do not, in fact, study the same
We propose a solution to mixed-methods research and the quantitative-
qualitative debate. Qualitative and quantitative research methods have grown out
of, and still represent, different paradigms. However, the fact that the approaches
are incommensurate does not mean that multiple methods cannot be combined
in a single study if it is done for complementary purposes. Each method studies
different phenomena. The distinction of phenomena in mixed-methods research
is crucial and can be clariﬁed by labelling the phenomenon examined by each
method. For example, a mixed-methods study to develop a measure of burnout ex-
perienced by nurses could be described as a qualitative study of the lived experience
of burnout to inform a quantitative measure of burnout. Although the phenomenon
‘burnout’ may appear the same across methods, the distinction between “lived
experience” and “measure” reconciles the phenomenon to its respective method
This solution differs from that of merely using the strengths of each method to
bolster the weaknesses of the other(s), or capturing various aspects of the same phe-
nomena. This implies an additive outcome for mutual research partners. Based on
REVISITING THE QUANTITATIVE-QUALITATIVE DEBATE 51
this assertion, qualitative and quantitative work can be carried out simultaneously
or sequentially in a single study or series of investigations.
Given that we have returned to debate in a no-debate world, what is the outlook
for mixed-paradigm research? As Phillips (1988a) points out, it may be that quant-
itative and qualitative approaches are inadequate to the task of understanding the
emerging science of wholeness because they give an incomplete view of people
in their environments. Perhaps in a “Kuhnian” sense, a new paradigm is in order,
one with a new ontology, epistemology, and methodology. Alternatively, we have
proposed seeking complementarity which we believe is both philosophically and
practically sound. This solution lends itself to new standards for mixed-paradigm
research. We hope that future guidelines which assess the quality of such research
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